Entity Framework – Code Only Looking Good

Jason — Sat, 12 Dec 2009 04:53:36 +0000

The release described in this post is no longer current.
Entity Framework 4.1 RTW is now available.

I’ve been hearing rumors Entity Framework (EF) is more robust now. I did a few searches and found the latest version EF CTP2. I was happy to find EF has a “code only” method for generating the database schema and a good take on configuration. If you are intrested in the code only method check out this walk through. I went through it and built my own application to get a handle on this new feature. Here were the steps I took to get up and running. You will need Visual Studio 2010, SQL, and CTP2 version of EF. 1) Install CTP2 Entity Framework Preview 2 2) Create a new class library project in your solution. This will be for your objects that will get mapped to the database. I named mine “UserSchema”. In this project you are just creating normal classes without any references to EF. Below are the two classes I used for testing. Notice they have no meta tags or any other tags that would be EF specific.

   public class Profile
    {
        public Profile() { }
        public int ID { get; set; }
        public string Title { get; set; }
        public string Description { get; set; }
        public string PermaUrl { get; set; }
        public DateTime Created { get; set; }
        public DateTime? LastSeen { get; set; }
    }

    public class User
    {
        public User() { }
        public int ID { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string UserName { get; set; }
        public string Password {get; set;}
        public ICollection Profiles { get; set; }
    }

3) Next create a new class project in your solution for your EF models. I called mine UserManager.Model. I think it is good to make a seperate project as this is going to setup all your class context for connecting to EF. You will also need to add a project reference to the project that has your objects which you want to be mapped in the database and a reference to Microsoft.Data.Entity.CTP and System.Data.Entity.

public class UserModel : ObjectContext
    {
        public UserModel(EntityConnection connection)
            : base(connection)
        {
            DefaultContainerName = "UserModel";
        }

        public IObjectSet User
        {
            get { return base.CreateObjectSet(); }
        }

        public IObjectSet Profiles
        {
            get { return base.CreateObjectSet(); }
        }
    }

4) Create a new console application to automatically generate your database. I called mine “UserManager.GenerateDatabase”. This is the application that will use the object context to autogenerate the database. You can also do specific table configuration and other initialization. You can use a RegisterConfigurations method. The walk through above goes into more detail on that.

var builder = new ContextBuilder();
var connStr = ConfigurationManager.ConnectionStrings["UserDBConn"].ConnectionString;

var connection = new SqlConnection(connStr);

using (var ctx = builder.Create(connection))
{
    if (ctx.DatabaseExists())
        ctx.DeleteDatabase();
     ctx.CreateDatabase();

My project and auto generated tables ended up looking like this: So after going through this quick setup I got a taste of what is to come. I’m still going to stick with ActiveRecord for my ORM but I think EF will definitly be an option in the future. Also, the code only mode will be a little more comfortable for people who have an ActiveRecord background. Entity Framework blog posts

Jason Rowe » .net4

Entity Framework – Code Only Looking Good